Liquid fuel injectors



p 6, 1958 J. w. wHlfsoN 2,852,308

LIQUID FUEL INJECTORS Filed Oct. 1, 1956 loo lOl Frq.2

INVENTOR.

drawings nited States Patent 2,852,308 LIQUID FUEL INJ'ECTORS John W.Whitson, New York, N; Y;; assignor of one-half to Mrs. Clare H. Whitson,New Yorlg-N. Y.

Application October 1, 1356, Serial No. 6135037 14 Claims. 61. m -167.2)

My invention relates to impfdiiemerits in liquid tun injectors which areused to introduce liquid fuel into a combustion space in which fuel isbiirfied.

The object of the invention is to provide an injector which willintroduce a metered fuel charge iiit o a busti'on space; the metering ofthe fuel t'zhaifige being accomplished through the instrumentality of'm'eans; which Utilizes" use p'hendmenon of the compi'ssiliility ofliqllids'.

A further object is to provide means to yary the t me: ity at the fuelchambers of the liquid fiiel injectdi-s' illustrated inmy recently filedapplication for'pate'iit upon Liquid Fuel Injectors, Serial Number612,398, filed Sep tihbel 27; 1956 and iud as Patefit 2,798,769 6i July9, 1957.

A further object is to provide an injector having its mechanismsactuated through the instrumentality of magnetic attraction. With theabove mentionedand other objects view,- the invention consists in thenovel construction and cont bination of parts hereinafter described;illustratedin the accompanying drawings, and set faith in the claimshereto appended, it being understood thatvarious changes iii form,proportion, size, location and minor details of con struction within thescope of the claims may be resorted to without departing from the spiritor sacrificing any of the advantages of the invention. Referring to theFig. l is a sectional view through a liquid fuel injector.

Fig. 2 is a wiring diagram illustrating the elecirical control system ofthe injector shown in Fig. l.

Fig. 3 is a sectional view of a modificationof the in jector shown inFig. 1'.

Fig. 4 is a wiring diagram illustrating the electrical control system ofthe injector shown in Fig; 3;

In detail the construction illustrated in the drawings comprises anouter casing 1 composed of sections of non-magnetic material which arejoined together by the plug members 2 which divide the casing into thefuel chambers" 3 and 4 which are connected by the" openings 5 in theplugs 2.

Chambers 3 are closed at their outer ends by the caps 6 which arethreaded to receive the fuel line 7 which is connected to a source offuel supply that can be subjected to substantially constant pressure ora variable pressure as the occasion requires.

Chamber 4, at the right of Fig. l, is closed-a't'it's outer end by thecap 8 which is threaded to receive the casing 1 and is threaded as at 9for screwing into an opening leading into a combustion space C in whichliquid fuelis to be burned. v

Cap 8 has an orifice 10 in which valve 11 is seated; valves 12 areseated in the openings 51 of the plugs 2. All of the valves have grooves13 formed therein to allow for the free passage of fuel in the chambers3 and 4-.

All of the valves have coned ends 14 and a: spring 15 which tends tounseat-the valve. The springs 15 cause the valves to bear against theconed shaped ends; of: the. movable valve obstructing elements 17, eachis influenced ice to move away from its valve obstructing position by aspring 18.

"Each of the elements 17 has a stem 19"which extends through an opening19 in a plug 20 which is composed of magnetically attractive material;the stem 19 abuts against the movable solenoid core 21 of a solenoidcoil 22 or 23 which are secured to the. casing 1 and are provided with acasing 24 composed of ironi npregnated plastic or other suitablemagnetically attractive material.

Plug's' 25 seal the chambers 3 and 4 and the plugs 25 of the chambers 4have tapped openings fpr' the reception of a volume adjusting screw 26which is provided with a lock nut 27. u

The above described elements are duplicated at the left of Fig. 1 exceptthat chamber 4, at the left; is closed at its outer end by a cap 28which is ta'ppedto receive a fuel return line 29 which runs to a fueltank. The cap 28 has an opening 28 in which valve 11 is seated.

The horizontal member of the casing 1, which .joins the fuel chambers 4,is provided with the plugs 30 and 30' to form a chamber 31 for thereception of the piston 32 which is the movable core of the solenoid 33which is mounted to slide on the horizontal member of the casing. Acasing 34 composed of magnetically conductive material encloses the coil33.

A gear rack 35 is mounted on the casing 34 and it en'f gages the wormgear 36 which is journaled in the brackets 37 which can be secured tothe apparatus on which the in jector is mounted. p

The plugs 30 and 30 each have an opening 38' which connects the chamber31 with the chambers 4;

Fig. 2; illustrates a source of electrical energy which isconnected toall of the solenoid coils by wire 101 and to solenoid coil 33 and atimer 102 by Wire 103; timer brush 104 is connected to solenoid coils 22and timer brush 105 is connected to solenoid'coils 23'. Thesolenoidcoils are normally maintained energized.

Operation Solenoid coils 22 and 23 are normally energized and eachattracts its movable core 21 towards the plug 20 to bear against thestem 19 of the valve obstructing ele-' ment 17 to maintain the element17 in its valve obstructing position, as illustrated in Fig. l, to holdits valve 11 or 12 seated. V

The timer 102 cycles to alternately de-energize the solenoid coils 22and 23 so that the springs 18 can move their elements 17 from theirvalve obstructing positions Solenoid coil 33 is normally energized andserves to maintain the piston 32 centered with the solenoid coil 50 thatwhen the solenoid coil is moved, through the instrumentality of the gearrack 35 and the worm gear 36, the piston willbe moved in the chamber31'.

The dotted lines F indicate the path of the magnetic flux in thesolenoids when they are energized.

With the chambers 4 and 31 filled tocapacity'with liquid fuel at normaldensity and with an' assumed density that would be substantially equalto 3000 poundsper square inch constant pressure on the fuel in thechambers 3 and the, fuel line' 7 then when the timer 102 is cycled coils22 will be de-energized and each of their springs 18 'willmove its valveobstructing element 17 out of its valve obstructing position so that thesprings 15' will on seat their valves 12 to permit fuel-to flow intoeach chamher 4 and raise the density of the fuel in the chambers 4 and31- to the density of the fuel in the chambers 3; coils 22 are thenenergized to seat their valves 12 and seal the chambers 4, with thechambers 4 and 31 containing fuel of substantially the same density asthe fuel in chambers 3. v v

The fuel capacity of the chambers 4 also includes the fuel contained inthe openings 38 in the plugs 30 or 30' the cylinder between the plugs 30and 30' minus the volume of the piston 32.

The piston 32 is movable to include all or any portion of the fuelcontained in chamber 31 with the volume of fuel contained in eitherchamber 4; a

With the piston positioned against the plug 30 the amount of fuel thatwill enter the chamber 4 at the right of Fig. 1 will approximate 1% ofits fuel capacity and I the amount of fuel that will enter the chamber 4at the left of Fig. 1 will approximate 1% of the fuel capacities of thechambers 4 and 31, if it is assumed that the modulus of elasticity ofthe fuel approximates that of water.

Experiments show that the alteration in volume of liquids isproportional to the density, hence the relation between the changes ofvolume when under pressure may be expressed:

Let

V K r K=from 320,000 to 300,000 pounds per square inch.

Thus water is reduced in bulk or increased in density by 1% when under apressure of 3000 pounds per square inch. This is quite apart from thestretch of the containing vessel.

When coils 23 are de-energized valves 11 will lift from their seatsandsubstantially 1% of the fuel contained in the chamber 4, at the rightof Fig. 1, will be discharged through the orifice into combustion spaceC and substantially 1% of the fuel contained in the chamber 31 and thechamber 4, at the left of Fig. 1, will be discharged into the returnline 29.

The discharge of fuel from the chambers 4 reduces the fuel remaining inthem and in chamber 31 back to its normal density. 1

Coils 23 are then energized to seat the valves 11 and the injector isready for another cycle.

The position of the piston 32 in chamber 31 determines the amounts offuel that will be discharged through the orifice 10 and into return line29; if the piston is positioned in the center of chamber 31 then equalamounts of fuel will be discharged from each of the chambers 4; with thepiston against the plug 30 the minimum amount of fuel will be dischargedthrough the orifice 10 and the maximum amount of fuel will be dischargedinto return line 29; with the piston against the plug 30' the maximumamount of fuel will be discharged through the orifice 10 and the minimumamount of fuel will be discharged into return line 29.

When solenoid coil 33 is energized the piston 32 will be magneticallyheld to move with the coil when the worm gear 36 is turned and alsomagnetically held to resist movement during a time interval when thepressure against the ends of the piston differs due to a variance in therate of fuel discharge from the chambers 4.

Moving the piston 32 serves to throttle the amount of fuel dischargedthrough the orifice 10; this is accomplished by varying the capacity ofthe fuel chamber to accommodate varying amounts of fuel of substantiallyconstant density; with the piston stationary the injector is selfmetering as to successive fuel charges.

In the manufacture of a series of injectors differences in volume of thefuel chambers may occur, in which event the volume adjusting screw 26will be positioned to normalize the volume of the fuel chambers.

Figs. 3 and 4 illustrate the injector of Fig. 1 with a mechanicallycontrolled piston 32 instead of the magnetically controlled piston 32illustrated in Fig. 1; also solenoid coils'22 and 23', which are similarto the solenoid coils 22 and 23 of Fig.1, are illustrated as beingnormally 'de-energized.

Chambers 3 and 4 and the elements at the left of Fig. l have beeneliminated and the piston 32 extends from the casing 1 and has a gearrack 40 cut therein for engagement with a worm gear similar to the gear36 of Fig. 1; rotation of the worm gear will move the piston to vary thevolume of chamber 4 and throttle the discharge of fuel through theorifice 10 as described in the operation of the apparatus of Fig. 1.

The casing has a groove 41 formed therein for the collection of fuelthat may have leaked past the piston 32'; a pipe'42- returns any leakedfuel to a fuel tank.

Plugs 25' seal the chambers 3 and 4 as do the plugs 25 of Fig. l. Theplug 25 serves as an element of the solenoid coil to attract the movablecore 43. Dotted lines F indicate the path of the magnetic flux in thesolenoids when they are energized.

The movable core 43 has a coned end 16' which is maintained against theconed end 14 of the valve 11 by a spring 44 to hold the valve seated asdescribed and illustrated in Fig. 1. q The solenoid coil 22 and itsrelated elements would be constructed as illustrated for coil 23' tofunction to seat and unseat the valve 12 as described and illustratedinFig. 1. a

Fig. 4 illustrates a source of electrical energy 200 which is connectedto solenoid coils 22 and 23' by wire 201 and to a timer 202 by wire 203,brush 204 of the timer is connected to coil 22' and brush 205 isconnected to coil 23'.

Operation Solenoid coils 22 and 23.,are normally de-energized; the timer202 cycles to alternately energize the coils to move their cores 43 fromtheir valve obstructing positions. a

With the chamber 4 filled to capacity with fuel at normal density andwith fuel at greater than normal density in chamber 3 and fuel line 7then when the timer is cycled coil 22' will be energized to attract itscore 43 towards the plug 25' and out of its valve obstructing positionsothat valve 12 will unseat and permit fuel to flow into chamber 4 andraise the density of the fuel therein to the density of the fuel inchamber 3; coil 22' is then tie-energized and the spring 44 moves thecore 43 back into its valve obstructing position to reseat the valve andseal chamber 4, with the chamber containing fuel of substantially thesame density as the fuel in chamber 3.

Coil 23' is then energized and its associated elements will function asabove described for coil 22 and valve 11 will be unseated to permit thedischarge of fuel through the orifice 10 as described and illustrated inthe operation of Fig. 1. e

The fuel chambers 4 of the injectors illustrated in my recently filedapplication for patent upon Liquid Fuel Injectors Serial Number 612,398,filed Sept. 27, 1956, and issued as Patent 2,798,769 on July 9, 1957,can be equipped with the piston 32' and its elements.

With the apparatus of Figs. 1 or 3 a pressure of 1500 pounds per squareinch on the fuel supply will pass onehalf of the amount of fuel intochamber 4, as compared to a pressure of 3000 pounds, 6000 pounds willpass twice as much fuel.

Thus varying the density of the fuel in combination with altering thecapacity of the fuel chamber provides a two way means to throttle thefuel that will discharge through the orifice 10.

' My invention-provides a method for operating liquid fuel injectorswhich utilizes the theory of the compressibility of liquids for meteringconsecutive fuel charges and injecting them into a combustion space, anew discovery in this art.

Leakage of fuel when under high pressure has been a poor quality featureof fuel injectors designed to meter and inject fuel in mechanicalfwi'tiifan engi e cycle; my injector overcomes this. asgits movableelements are completely sealed within the injector casing and do notrequire outside mechanical connections to operate them, since they areoperated through the 'instrument'ality of magnetic attraction, a newdiscovery in thisart.

My invention provides for utilizing electromechanical devices to timethe injection cycle, a new discovery in this art. V v The drawings donot shown construction details such as removable seats for the valves,a. nozzle tip for orifice 10, etc., as would be the case in commercialdesigns; only the elements necessary to disclose the invention are shownso that the relationship of the common elements, of the severalinjectors illustrated, may be clearly seen.

While the foregoing describes the injectors as operated with liquid fuelit is to be iifiderst'ood that they will operate with matter in a fluidstate whether liquid or gaseous.

When the term normal density is used it may also mean the density atatmospheric pressure.

Having described my invention above in detail I wish it to be understoodclearly that many changes may be made therein without departing from thespirit of the same.

I claim:

1. The method of operating an injector having a fluid chambercomprising: sealing the chamber against the discharge of fluid; fillingthe chamber with fluid at normal density; unsealing the chamber forfluid to enter and increase the density of the fluid contained thereinabove its normal density; sealing the chamber, with the fluid containedtherein at the increased density; unsealing the chamber for a portion ofthe fluid to discharge therefrom and reduce the fluid remaining in thechamber to normal density; then optionally cause the volume of thedischarge to vary by altering the fluid capacity of the chamber.

2. The method of operating an injector having a fluid chambercomprising: sealing the chamber against the discharge of fluid; fillingthe chamber with fluid at normaldensity; unsealing the chamber for fluidto enter and increase the density of the fluid contained therein aboveits normal density; sealing the chamber, with the fluid containedtherein at the increased density; unsealing the chamber for a portion ofthe fluid to discharge therefrom and reduce the fluid remaining in thechma'ber to normal density; then optionally cause the volume of thedischarge to vary by altering the fluid capacity of the cham ber throughthe instrumentality of magnetic attraction.

3. The method of operating an injector having a fluid chambercomprising: sealing the chamber against the discharge of fluid; fillingthe chamber with fluid at above normal density, While maintaining thechamber sealed against the discharge of fluid; unsealing the chamber fora portion of the fluid to discharge therefrom and reduce the fluidremaining in the chamber to normal density; then optionally cause thevolume of the discharge to vary by altering the fluid capacity of thechamber.

4. The method of operating an injector having a fluid chambercomprising: sealing the chamber against the discharge of fluid; fillingthe chamber with fluid at above normal density, while maintaining thechamber sealed against the discharge of fluid; unsealing the chamber fora portion of the fluid to discharge therefrom and reduce the fluidremaining in the chamber to normal density; then optionally cause thevolume of the discharge to vary by altering the fluid capacity of thechamber through the instrumentality of magnet attraction.

5. The method of operating an injector having a fluid chambercomprising: sealing the chamber against the discharge of fluid; fillingthe. chamber with fluid at normal density; subjecting the fluid to asource of pressure to increase its density above normal density whilemaintaining the chamber sealed; unsealing the chamber for a portion ofthe fluid to discharge therefrom and reduce the fluid remaining in thechamber to normal density; then optionally cause the volume of thedischarge to vary by altering the fluid capacity of the chamber.

6. The method of operating an injector having a fluid chambercomprising: sealing the chamber against the discharge of fluid; fillingthe chamber with fluid at normal density; subjecting the fluid to asource of pressure to increase its density above normal density whilemain taining the chamber sealed; unsealing the chamberfor a portion ofthe fluid to discharge therefrom and reduce the fluid remaining in thechamber to normal density; then optionally cause the volume of thedischarge to vary by altering the fluid capacity of the chamber throughthe instrumentality of magnetic attraction.

7. The method of operating an injector having afluid chamber comprising:sealing the chamber against the discharge of fluid; filling the chamberwith fluid at normal density; subjecting the fluid to a source ofpressure a fluid capacity of the chamber.

8. The method of operating an injector having a fluid chambercomprising: sealing the chamber against the discharge of fluid; fillingthe chamber with fluid at normal density; subjecting the fluid to asource of pressure to increase its density above normal density; sealingthe chamher and the fluid contained therein from the source of pressure;unsealing the chamber for a portion of the fluid to discharge therefromand reduce the fluid remaining in the chamber to normal-density; thenoptionally cause the volume of the discharge to vary by altering thefluid capacity of the chamber through the instrumentality of magneticattraction.

9. A fluid injector comprising in combination: a chamber for thecontainment of fluid; means to fill the chamber with fluid at abovenormal density; means to seal the chamber after it is filled with fluidabove normal density; means to unseal the chamber, when it is filledwith fluid above normal density, for a portion of the fluid above normaldensity to discharge from the chamber which discharge reduces thefluidremaining in the chamber to normal density and means to alter the fluidvolume of the chamber.

10. A fluid injector comprising in combination: a chamber for thecontainment of fluid; means to fill the chamber with fluid at abovenormal density; means to seal the chamber after it is filled with fluidabove normal density; means to unseal the chamber, when it is filledwith fluid above normal density, for a portion of the fluid above normaldensity to discharge from the chamber which discharge reduces the fluidremaining in the chamber to normal density; means to alter the fluidvolume of the chamber and means to move the last named means through theinstrumentality of magnetic attraction.

11. A fluid injector comprising in combination: a sealed chambercontaining fluid at normal density; means to unseal the chamber for theentry of fluid above normal density which entry increases the density ofthe fluid in the chamber; means to seal the chamber after the entry offluid above normal density; means to unseal the chamber, when it isfilled with fluid above normal density, for a portion of the fluid abovenormal density to discharge from the chamber which discharge reduces thefluidremaining in the chamber to normal density and means to alter thefluid volume of the chamber.

12. A fluid inject-or comprising in combination: a sealed chambercontaining fluid at normal density; means to unseal the chamber for theentry of fluid above normal density which entry increases the density ofthe fluid in the chamber; means to seal the chamber after the entry offluid above normal density; means to unseal the chamber, when it isfilled with fluid above normal density, for a portion of the fluid abovenormal density to discharge from the chamber which discharge reduces thefluid remaining in the chamber to normal density; means to alter thefluid volume of the chamber and means to move the last named meansthrough the instrumentality of magnetic attraction.

13. A fluid injector comprising in combination: a chamber containingfluid above normal density; means to seal the chamber against thedischarge of fluid above normal density; means to unseal the chamber,when it is filled with fluid above normal density, for a portion of thefluid above normal density to discharge from the chamber which dischargereduces the fluid remaining in the chamber to normal density and meansto alter the fiuid volume of the chamber.

14. A fluid injector comprising in combination: a chamber containingfluid above normal density; means to seal the chamber against thedischarge of fluid above nor mal density; means to unsealthe chamber,when it is filled with fluid above normal density, for a portion of thefluid above normal density to discharge from the chamber which dischargereduces the fluid remaining in the chamber to normal density; means toalter the fluid volume of the chamber and means to move the last namedmeans through the instrumentality of magnetic attraction.

References Cited in the file of this patent UNITED STATES PATENTS598,035 Towle Jan. 25, 1898 1,635,220 Palmer July 12, 1927 1,750,872Bremer Mar. 18, 1930

